Processes for granulating and milling fluid melts and especially slags or metal melts and glass melts in which the melts are sprayed as a fluid stream into a cooling chamber have already become known in different versions. EP 1038976 A1 shows and describes a process of this type in which, for improving the material properties of the granulate, the procedure is such that the sprayed melt droplets in the spray stream are heated to temperatures between 1500° C. and 1750° C. by afterburning of hot gases in the inside of the cooling chamber, whereby the subsequent cooling chamber is designed with radiant heat sinks. This method is based on the consideration that the cooling speed of particles is dependent on the diameter of the particles, whereby radiant cooling increases greatly with increasing particle size. However, spraying that is as fine as possible also has the advantage that when e.g. aggregates will be produced for the cement industry, a subsequent grinding process can be dispensed with if an adequately fine division of the droplets and/or particles has been carried out. Fluid slags, and especially oxidic slags, generally lie at temperatures between 1250° C. and 1650° C. whereby the viscosity of these types of melts decreases with increasing temperature. A decreasing viscosity has the consequence that it is easier to produce especially small particles during spraying. In EP 1038967 A1, this was mainly the goal with respect to efficient radiant cooling. In WO 01/62987 A1, a device for pulverizing fluid melts, and especially oxidic slags or glasses, was suggested in which a slag tundish is provided which has an outlet opening. Into this outlet opening, a lance dips for ejecting gases or steam with the formation of a ring slot. The lance is surrounded by an outer pipe that is height-adjustable, independently of the height adjustability of the lance, so that lowering and raising the outside pipe can adjust the width of the ring slot and thus the material flow of the melt while propellant gas can be brought in with the inner lance. Propellant gas can be brought in with the inner lance. Preferably, autothermic-generated steam is used here as a propellant gas stream, whereby for an appropriate heating or overheating of the steam a relatively high effort has to be made. Further improvements and modifications of this process principle can be found in WO 02/04687 A1 and WO 00/44942, among others. In this case, a combustion exhaust gas is used for ejecting the melt whereby hot combustion exhaust gases, especially after complete combustion, are used for spraying the melt. Overall it has been observed that the use of a propellant gas with especially high temperatures leads to a better grinding of the stream and thus to a finer distribution because of the gas viscosity that is increased due to the higher temperature whereby the preparation, compression, and distribution of the propellant gases involves relatively high effort.